A former journalist, Mr Santana is well known for producing dramatic, big-budget campaign videos appealing to poorer voters.

Mr Santana had called the accusations "unfounded". And he had harsh words for the investigation, saying that Brazil was currently living in a "climate of persecution".

If the investigating judge accepts the allegations against him, Mr Santana will be jailed.

In Brasilia, a special Senate commission has begun hearings ahead of a vote on whether the whole Senate should take on impeachment proceedings against President Rousseff.

A plenary Senate vote is widely expected to take place around 11 May.

Across the country, pro-government supporters blocked major roads in cities in nine Brazilian states during Thursday's morning rush-hour to call for the halt of impeachment proceedings against President Rousseff.

In Sao Paulo, the city saw hundreds of kilometres of traffic jams which formed behind roadblocks of burning tyres.